Metallurgical method.



' 1,083,909. NoDrawing. I

srrn rps ii mui giT OFFICE! Hans xuznn, or nnnmr, new vmmfn,

AUSTRIA QHUNGABY, AND EDGAR WEDEKIND,

or s'rmssnono, GERMANY, nssronons '10 GENEBSAL' nnncrnrc OOMPANY,-'A core roiwrrou or NEW YORK.

pecifleation of Letters Patent A plicatio med June 10, 1910. serial No. 566,222;

a 'unrannonorcnn METHOD:

Patented Ma. 3, 1914.

- TbaZZ may concern:

- Be a known that we, time new, a sub -"at Baden, near. Vienna ject of the Emperor of- Germany Empire oi Austria- Hungary and EDGAR wnonnmo, a subject of the Emperor of Germany, residing at Strassbu'rg, Germany, have invented certain new and useful Improvements in Metallurgical Methods, of which the following is a specification.

Our invention relates to a method of obtaining metals from their compounds and residing more particularly from their oxide and-also comprises a metalnow for the first time produced in a'condition of substantial purity. We have found this 'method particularly applicable to the production of.pure zircop the action of alkaline metals, principalliy sodium on halogen compounds or doub halogen compounds of the metals to be .pr6-' duced. The results oi these processes have been very unsatisfactory, and their product has been of a low degree of purity. These" methods are particularly disadvantageous when employed on a large scale, the alkaline metals readily distilling oil at the high reaction temperatures necessary to the reaction; or, if the reaction is carried out in closed apparatus, giving rise to a dangerously highpressure. By the use of our invention, these metals may be readily and directly produced from their oxids in a con dition of purity;

For the purpose of effecting reduction of these oxids, 'We employ metallic calcium. We find that metallic calcium reacts with the oxide of the refractory metals referred to very energetically. "The calcium practically does not distil at. all at. the reaction temperatures; and at such relatively high temperatures (for example, 800C. or more) becomes more active and shows a greater ,afiinity for chlori'n, oxygenfietc, and seizes upon them even more eager y than sodium, for example.. By our method, the refractory metals referred to are obtained in an extremely finely divided and amorphous state,

even when the reaction goes ,on slowly.

. This makes possible a very thorough cleansing of the product and facilitates its transformation into the colloidal state.

To enable those skilled in the art to pracuse our invention to the best advantage, we

will describe in detail its application to the roduction of pure zirconium and we will hen indicate what considerations must be borne in mind when it is used for the production of other metals.

In a suitablemixing or grinding device, We make an intimatejmixt1ireof50 grams zirconium oxid and 72 grams of metallic calcium, the calcium for this purpose being preferably in the form of the finest possible chips or in the still finer form of metallic sponge or powder. This amount of calcium is considerably in excess of that which enters into reaction with the zirconium oxid;

but the excess insures complete reduction of. Y

the oxid and is easily removed. The mixture thus obtained is placed as quickly as possible in a vessel suitable for the reaction, the oxygen and nitrogen of the air being preferably excluded during the transfer. For this purpose may be employed a cylindrical crucible or bomb which may be closed air tight by a cover furnished with a metal cook; or, if preferred, a spherical apparatus may be used. The apparatus used should be made of the most refractory metals that can conveniently be employed, such metals as platinum steel, and the like, being suitable. After. it has been charged and closed, the apparatus is exhausted with. a vacuum pump to an absolute pressure of from 0.5 'to' 0.1 mm. of mercury. The cock is then closed and the bottom of the apparatus heatedby 'means of a strong flame until the reaction between the zirconium oxid and calcium beglowing begins, the external heating is stopped. The finer the powder of the mixlure, the more lively is the reaction, and the more readily does it occur. Under some c 1rcumstances, it may be caused by electric 1gnition, as, for, example, by the use of a platinum wire heated to incandescence by current or by a high voltage spark. Spontaneous ignition has repeatedly been observed, even whenthe mixture was in contact with the air.

The reaction appears. to take. place according to the equation and washed with water until a reaction indicating the presence of calcium can no longer be obtained. The water is in turn driven off by alcohol and ether, and the powderis thoroughly dried, preferably in a. vacuum. The drying may be rendered complete by heating the product for several hours in a high vacuum at about .1 mm. of mercury pressure to a relatively high temperature of, for example, 300 or 400 degrees C. If the product is also to be completely deprived of gases, it must be further heated to about 1000 O. and maintained at this temperature until -the vacuum gage shows a constant pressure. If the heating is carried above this temperature, the metal powder sinters or welds itself into granules and small compact lumps. The metallic zirconium thus obtained shows a content of 96 per cent. free zirconium, the remainder consisting of zirconium oxid, about 3 per cent. of iron from the apparatus in whichthe reaction was carried on, and traces of zirconium nitrid. Using the method of this invention, it has even been found possible to obtain a product containing as much as 97 to 98 per cent. zirconium. If access of oxygen and nitrogen to the metal is prevented throughout, a metal free from oxid or nitrid is obtained. The met-a1 has a. brilliant metallic appearance, has a specific gravityof about 6.2, and a normal atomic heat of about 6.4. It is a good conductor of electricity and is very resistant to chemical re-agents,with the exception of hydrofluoric acid. All these properties diifer substantially from those hitherto ascribed to zirconium. This is owing to the fact that the alleged zirconium hitherto produced contained very high percentages of impurities, as for example, oxid and carbid.

If the treatment of the mass resulting from the reaction in the bomb with acids is often repeated, it is very easy to obtain the metal in colloidal form, so that the process described is exceedingly well adapted for themanufacture of articles of the refractory metals named, such as filaments, by colloidal methods. 4

The oxids of titanium and thorium can be reduced with calcium according to this process in the same manner as zirconium oxid. It is to be noted that the reduction of products are less stable against treatment with water and acids. With the metals which are less susceptible to the components of the atmosphere, such as chromium,

tungsten, and molybdenum, the reaction may be carried .on in apparatus: which has not been evacuated, tightly closed crucibles being quite satisfactory.

The new method offers considerable advantages over old methods in the case of these metals for various reasons, such as the 1 ready reaction of calcium with water, the easy solubility of calcium and of its oxid and hydroxid in water and in dilute acids, and, the facility with which salts may be washed out of the product by water as well as alcohol.

What we claim as new and desire to secure by Letters Patent of the United States, 1s,

1. The method of producing refractory metals which consists in reducing oxygen compounds of such metals -with metallic calcium in an inert environment.

2. The method of producing pure refractory metals which consists in reducing metallic oxids of such metals with calcium in a vacuum.

3. The method of producing metal which consists in heating an intimate mixture of a compound of the metal to be reduced and metallic calcium to cause reaction, and excluding oxygen and nitrogen from the reaction zone during the process of the reaction.

4. The method of producing substantially pure zirconium which consists in reducing zirconium oxid with calcium in an inert environment.

5. The method of producing pure zirconium which consists in reducing zirconium oxid with calcium and treating the reaction product to eliminate all substances except the metal, the reactions and treatment being effected in the absence of nitrogen and oxygen. I

6. The method which consists in forminga mixture of-zirconium oxid and finely divided calcium, inclosing this mixture in a vessel adapted to exclude oxygen and nitrogen, applying heat to the vessel to cause '1,oss ,eoe"' v B reaction, cooling the same, and treating the unto-Set my hand this 17th day of May, products of reaction to eliminate all except 1910. F

zirconium. DR. HANS KUZEL.

7. The method of producing metal which PROF. DR. E. WEDEKIND. 5 consists in heating a metallic compound to Witnesses to Kuzel:

be reduced in contact with calcium in a sub- I ANDREUS HIPGK,

stantial vacuum. AUGUST FUGGER.

In witness whereof, I, HANS KUZEL, have Witnesses to Wedekind: hereunto set my hand this 10th day'of May, FRITZ WEDEKIND, 10-1910, and I, EDGAR WEDEKIND, have here- J. M. Bowcocx. 

